This invention relates generally to gas turbine engines, and more specifically to gas turbine engine assemblies that each include a booster compressor coupled to a low-pressure turbine and methods of assembling the same.
At least some known gas turbine engines include a fan, a core engine, and a power turbine disposed downstream from the core engine. The core engine includes at least one compressor, a combustor, a high-pressure turbine and a low-pressure turbine disposed downstream from the core engine. More specifically, the compressor and high-pressure turbine are coupled through a shaft to define a high-pressure rotor assembly. Air entering the core engine is mixed with fuel and ignited to form a high energy gas stream. The high energy gas stream flows through the high-pressure turbine to rotatably drive the high-pressure turbine such that the shaft, in turn, rotatably drives the compressor.
The gas stream expands as it flows through the low-pressure turbine to drive the fan through a second shaft. To facilitate increasing engine efficiency, at least one known gas turbine engine includes a counter-rotating low-pressure turbine that is coupled to a counter-rotating fan and a booster compressor.
An outer rotating spool, a rotating frame, a mid-turbine frame, and two concentric shafts, are installed within the gas turbine engine to facilitate supporting the counter-rotating low-pressure turbine. The installation of the aforementioned components also enables a first fan assembly to be coupled to a first turbine and a second fan assembly to be coupled to a second turbine such that the first fan assembly and the second fan assembly each rotate in the same rotational direction as the first turbine and the second turbine, respectively. However, the overall weight, design complexity and/or manufacturing costs of such an engine are increased.